| Title |
The Improvement of the Efficiency of Geothermal Heat Pump for the Supply of Cold Water and Hot Water Heat Source for Conveyance Energy Saving |
| Authors |
Deokgeun Kim ; Hiki Hong ; Sungrag Lee |
| DOI |
https://doi.org/10.6110/KJACR.2026.38.1.55 |
| Keywords |
반송에너지; 급탕열교환기; 지열 히트펌프; 대온도차 Conveyance energy; Domestic hot water heat exchanger; Geothermal heat pump; Large temperature difference |
| Abstract |
Geothermal heat pump (GHP) systems encounter several technical challenges during low-temperature operation, such as freeze-bursting of plate heat exchangers (HEX), a reduced coefficient of performance (COP), and difficulties in providing both chilled and hot water simultaneously. These issues stem from non-uniform circulation of the heat transfer fluid, low flow rates, and underutilization of the domestic hot water (DHW) HEX, leading to decreased system efficiency and potential breakdowns. This study proposes a high-efficiency GHP system utilizing a dual-load HEX, which can switch between series and parallel modes based on operational conditions. Furthermore, the total HEX area is effectively increased by incorporating the DHW HEX on both the heat source and load sides. The proposed system can consistently produce chilled water at 4℃ and hot water at 60℃, even under significant temperature differences, resulting in a reduction of return energy costs by up to 40%. Performance tests conducted in accordance with Korean industrial standards (KS) demonstrated excellent results, with a cooling COP of 5.1 and a heating COP of 3.4, indicating superior efficiency compared to conventional systems. These findings underscore the feasibility of a GHP system capable of simultaneously supplying hot and cold water while reducing return energy costs. |